Electric valve circuit



Feb; 20, 19404 i E. F. w. ALEXANDER'SON 90, 5

ELECTRIC VALVE CIRCUIT Filed Oct. 31, l936 Inventor: Ernst F W. Alexanderson,

Patented Feb. 20, 1940 PATENT OFFICE ELECTRIC VALVE CIRCUIT Ernst F. W; Alexanderson, Schenectady, N. Y., as

signor to General Electric Company, a corporation of New York OCT 14 1941 Application October 31, 1936, Serial No. 108,587

9 Claims.

My invention relates to electric valve circuits and more particularly to control and excitation circuits for electric discharge devices of the type employing ionizable mediums, such as gases or 5 pots.

In the control of electric discharge devices of the type employing ionizable mediums, such as gases or vapors, where the electric discharge is initiated by a control member associated with or 10 in the vicinity of the arc path, it is frequently desirable toprovide 'a control or excitation circuit which energizes the control member at pre-' determined points in the cycle of operation and which eil'ects de-energization of the control memlii ber upon initiation of the arc discharge. This type of control is of particular importance in connection with the control of electric discharge deviceshavingimmersion-ignitor control members; These control members may be constructed Q of a semi-conducting material having a relatively large specific resistivity, and are arranged to have an extremity thereof in contact with, or submerged in the mercury of an associated mercury-pool cathode.

- I An object of my invention is to provide a new and improved control circuit for electric discharge devices.

Another object of my invention is to provide a new and improved excitationcircult for elec Q tric discharge devices of the type employing control members oi the immersion-ignitor type.

In accordance with the illustrated embodiment of my invention, I provide a new and improved excitation circuit for controlling the energiza- 35 tion of control members of electric discharge.

devices. Electric discharge devices of the type employing immersion-ignitor control members are connected in an electric translating circuit for transmitting energy between two alternating 4. current circuits. A plurality of excitations are associated with the electric discharge. devices to render the devices conductive during predeter companying drawing ditically illustrates an embodiment of my invention as applied to an electric valve translating system for transmitting electrical energy between two alternating current circuits.

In the single figure of the accompanying drawing', my invention is diagrammatically illustrated as applied to control or excitation circuits for controlling electric valve means or electric discharge apparatus in an electric translating system. Electric valves l-l, inclusive, are employed to transmit electrical energy between an alternating current circuit 5 and an alternating current circuit 6 through a transformer I. For the purpose of explaining my invention, the electric discharge devices i-l, inclusive, have been diagrammatically illustrated as being of the type employing ionizable mediums, such as gasm or vapors, and including an anode 8, a mercurypool cathode 9, and an associated control member iii of the immersion-ignltor type. The immersion-ignitor control member ll may be constructed of a semi-conducting material having a relatively large specific resistivity relative to the resistivity of the associated mercury-pool cathode 9. One extremity of the immersionignitor control member I! may be placed in contact with the surface of the mercury-pool cathode 8 or may be submerged below the surface of the pool. 7

In order to control the conductivity of the electric discharge devices i-l, inclusive, I employ a plurality oi control or excitation circuits 44, inclusive. These excitation circuits render the electric discharge devices i4, inclusive, conductive in a predetermined order and permit these devices to conduct current during predetermined intervals. Each of the excitation circuits "-44 includes a source of alternating current I! which may be derived from the alternating current circuit 5. The excitation circuits ll-Il, inclusive, are similar in construction and arrangement and for the purpose of facilitating the description thereof, one of the excitation circuits, for example, excitation circuit H, will be considered in particular. A capacitance II is connected in the excitation circuit H and is arranged to be charged from the source of alternating current l5 through a transformer I! and a suitable unidirectional conducting device such as an electric valve iii; A suitable impedance such as a resistance i9 may be connected in series relation with the secondarywinding of transformer IT, the electric valve i8 and the capacitance ii to control the rate at which the capacitance ii is 55 HEISVSUZD charged. An auxiliary or control electric discharge device 20, preferably of the type employing an ionizable medium and having an anode 2|, a cathode 22 and a control member 23, is connected in the excitation circuit II to efl'ect perlodic discharge of capacitance I6 and hence to impress on the immersion-ignitor control member III of the associated electric discharge device I a transient positive potential of peaked wave form and of sufficient magnitude and duration to render the discharge device I conductive. This energization of the immersion-ignitor control member I is effected by means of a suitable inductive device, such as a transformer 24 having a primary winding 25 and a secondary winding 26 and which is energized in accordance with the periodic discharges of the capacitance I8. One terminal of the secondary winding 26 of transformer 26 is connected to the cathode 9 of the discharge device i and the other terminal of the secondary winding 26 is connected to the immersion-ignitor control member I 0.

I provide means compris ng a circuit 21 for con? trolling the excitation circuit II to effect deenergization of the immersion-ignitor I0 upon the initiation of an arc discharge in the arc discharge path of the device I. The circuit 21 comprises a serially-connected reactive element such as a capacitance 28 and a resistance 29 connected between the anode 8 and the cathode 9 of electric discharge device. I and which is responsive to the decay of voltage therebetween. A voltage which varies in accordance with the voltage appearing across the terminals of resistance 29 is introduced in the excitation circuit I I through a suitable means such as a transformer 30 having a primary winding 3| and a secondary winding 32.

The control electric discharge devices 20 in excitation circuits Il-Jd, inclusive, are rendered conductive in a predetermined order by means of a control circuit 33. The control circuit 33 may be energized from any suitable source of alternating current such as the alternating current circuit through any suitable phase shifting arrangement such as the rotary phase shifter 34. The output circuit of the rotary phase shifter 34 is connected to a primary winding 36 of a transformer 35 and serves to energize the transformer 35 and to control the phase of the potentials im pressed on the control members 23 of electric discharge devices 20. Secondary windings 31 of transformer 35 are each associated with a different one of the electric discharge devices 20 in excitation circuits I l-ll, inclusive, and each of these control circuits includes a current limiting resistance 38 and a suitable source of negative biasing potential such as a battery 39. The transformer 35 may be of the type designed to provide a voltage of peaked wave form.

The operation of the embodiment of my inven tion diagrammatically shown in the single figure of the accompanying drawing may be best explained by considering the electric valve translating system, when energy is being transmitted from the alternating current circuit 5 to the alternating current circuit 6 through the electric discharge devices I-4, inclusive. As will be well understood by those skilled in the art, during half cycles of one polarity of the voltage of circuit 5. electric dlccharge devices I and 4 will be rendered conductive to transfer energy to the alternatingcurrent circuit 6, and during half cycles of the opposite polarity, electric discharge devices 2 and 3 will be rendered conductive to transmit energy to the alternating current circuit 6. Let it be assumed that the rotary phase shifter 34 is adjusted so that the potential impressed on the control members 23 of the control discharge devices 20 are retarded in phase relative to the potentials appearing between the anode 8 and cathode 9 of the associated electric discharge devices I-4, inclusive. The excitation circuits II-ld, inclusive, will periodically effect energization of the immersion-ignitor control members Ill of the devices I-4, to render these devices conductive in the normal predetermined manner.

Considering in particular the operation of the excitation circuit II associated with electric discharge device I, the capacitance I6 will be charged from the source of alternating current I5 through the transformer H, the electric valve I8, and resistance I9, during positive half cycles of the voltage of this source. At the time determined by the phase position of the voltage impressed on control member 23 of the control discharge device 20, the capacitance I6 will be discharged through a circuit including the secondary winding 32 of transformer 30, the electric discharge device 20.

primary winding 25 of transformer 24, and the capacitance I6. The passage of this discharge current through the primary winding 25 of transformer 24 will impress on the immersion-ignitor control member 'I 0 of the electric discharge device I a positive transient voltage of peaked wave form effecting energization of the control member Ill and rendering the electric device I conductive. That is, the discharge of the capacitance I6 through electric discharge device 20 and transformer 24 serves to effect energization of the immersion-ignitor control member I0 of electric valve I during a predetermined interval or portion of the cycle of voltage of circuit 5. Prior to the initiation of the arc discharge within the electric discharge device I, the capacitance 28 in the circuit 21 will have been charged by virtue of the difference of potential existing between the anode 8 and the cathode 9 of the electric discharge device I. The upper plate of the capacitance 28 will have accumulated a positive charge so that, upon initiation of the arc discharge within the electric discharge device I, the capacitance 28 will discharge through a circuit including the anode 8, the associated arc discharge path, the cathode 9, the resistance 29 and the capacitance 28. The voltage appearing across the terminals of the resistance 29, and hence the voltage impressed across the primary winding 29 of transformer 39 will introduce in the excitation circuit I I through the transformer 30 a voltage of the proper polarity to control the excitation circuit II and to render the control electric discharge device 20 nonconductive by impressing on the anode 2| of this deing systems generally where it is desired to transmit energy between alternating current and direct current circuits or between alternating current circuits of the same or different frequencies.

While I'have shown and described my invention as applied to a particular system of connections and as embodying various devices diagrammatically shown, it will be obvious to those skilled in the art that changes and modifications may be made without departing from my invention, and I, therefore, aim in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In combination, an electric discharge device having an arc discharge path and having an anode, a cathode and a control member of the,

immersion-ignitor type for initiating an are discharge in said path, means tending to energize continuously said control member during, a predetermined interval of a cycle of anode-cathode voltage, and means responsive to the decay of voltage across said path upon the initiation of an arc discharge therein for controlling said firstmentioned means to effect de-energization of said control member during said predetermined inter- 2. In combination, an electric discharge device having an arc discharge path and having an anode, a cathode and a control member of the immersion-ignitor type for initiating an are discharge'insaid path, an excitation circuit tending to energize continuously said control member during a predetermined interval of a cycle of anode-cathode voltage, and reactivemeans responsive to the decay of voltage across said path forcontrolling said excitation circuit to de-energize said control member during said predeter- 'mined interval upon initiation of an are discharge in said path.

3. In combination, an electric discharge device having an anode, a cathode, and a control member, an excitation circuit tending to energize continuously said control member during a predetermined interval of a cycle of anode-cathode voltage to initiate'an arc discharge between said anode and said cathode, and means responsive to the decay of voltage between said anode and said cathode upon the initiation of an arc discharge therebetween to introduce in said'excitation circuita voltage to eiIect de-energization of said control member during 'said predetermined interval.

4. In combination, an electric discharge device having an anode. a cathode, and a control member of the immersion-ignitor type, an'excltation circuit for impressing on said control member a voltage of substantially peaked wave form to render said device conductive during a predetermined interval of a cycle of anode-cathode voltage, and means comprising a reactive element rea resistance connected across said anode and said cathode ior introducing in said excitation circuit a voltage to eflect de-energization of said control member upon the initiation of an are discharge in said device.

. 6'. In combination, an electric discharge device .having a control member, an excitation circuit tion of said control member, and means including a circuit for introducing in said excitation cir-,-v wit a voltage to render said second-mentioned electric discharge device nonconductive and to \effect de-energization of said control member upon the initiation of an arc discharge in said first-mentioned device.

7. In combination, an alternating current circuit, an electric discharge device connected thereto and having an anode, a cathode and an immersion-ignitor control member, an excitation circuit for energizing said control member to render said electric discharge device conductive comprising a source of alternating current, a capacitance connected to be charged from said source, a control electric discharge device for periodically discharging said capacitance and means responsive to the discharge of said capacitance for. impressing on said control member a transient positive voltage, and means comprising a serially-connected capacitance and a resistance connected across said anode and said cathode for introducing in said excitation circuit having an anode, a cathode and a control member o f-the immersion-ignitor type, an excitation circuit to energize continuously said control member during a predetermined interval of a cycle of anode-cathode voltage to initiate an arc discharge between said anode and said cathode, and means responsive to an electrical condition of said discharge device occasioned by the initiation of an arc discharge between said anode and said cathode for eiIec ing deenergization of said control member during said predetermined in- 9. In combination, an electric discharge device having an anode, a cathode and a control member of the immersion-ignitor type, an excitation circuit tending to energize continuously said control member during a predetermined interval of a cycle of anode-cathode voltage to initiate an arc discharge between said anode and said cathode comprising means for supplying current to said control member, and means responsive to a predetermined electrical condition of said discharge device incident to the establishment of an arc discharge between said anode and said cathode for rendering said last mentioned means ineiiective thereby effecting deenergization of said control member during said predetermined interval.

ERNST F. W. ALEXANDERSON.

DISCLAIMER- 2,190,759.Ernst F. W. Ale'wanderson, Schenectady, N. Y. Enmcrmc VALVE Cmcm'r.

Patent dated February 20, 1940. Disclaimer filed May 5, 1941, by the assignee, General E Zeatm'c Oompany.

Hereby enters this disclaimer to claims 8 and 9 in said patent.

[Ofioial Gazette May 27,1941] 4 DISCLAIMER- 2,190,759.-Ernst F. W. Alemanderson, Schenectady, N. Y. Emc'rmc VALVE 61mm.

Patent dated February 20, 1940. Disclaimer filed May 5, 1941, by the assignee, General Eleotfic Oompany. Hereby enters this disclaimer to claims 8 and 9 in said patent.

[Ofiioz'al Gazette May 27, 1.941.] 

